A Study of Galfenol-Based Magnetostrictive Energy Harvester Under Different Vibrations

When an external magnetic field is applied to a ferromagnetic material like Galfenol, Terfenol-D, etc., they generally tend to expand or contract. This property of the materials is known as magnetostriction. Magnetostrictive materials thereby convert the applied electromagnetic energy into harness able mechanical energy and can be utilized in various applications. The Villari effect or the inverse magnetostrictive effect is just the opposite of Joule's effect of magnetostriction. It refers to the phenomenon in which the application of external stress causes a change in the magnetic domains of the materials and thus an electromotive force is generated in the material. In other words, in inverse magnetostriction, the mechanical energy thus gets converted to electromagnetic energy. This electromagnetic energy or rather the voltage obtained is put to various other applications such as a source of self-sustained power supply of wireless sensor networks especially in harsh and hostile environments. Also, it can be said that this effect of inverse magnetostriction is related to ambient vibrations and thus can also to put to various practical uses such as the health monitoring of civil structures. But for putting the magnetostrictive energy sensors in that use, it's important to decide which of the parameters between voltage and frequency can be the deciding factor. The paper tries to find out the same by the application of various hardware equipment and understanding the relation.